package com.hmdp.service.impl;

import cn.hutool.core.bean.BeanUtil;
import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.baomidou.mybatisplus.extension.conditions.query.QueryChainWrapper;
import com.hmdp.dto.Result;
import com.hmdp.dto.UserDTO;
import com.hmdp.entity.Follow;
import com.hmdp.entity.User;
import com.hmdp.mapper.FollowMapper;
import com.hmdp.service.IFollowService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.service.IUserService;
import com.hmdp.utils.RedisConstants;
import com.hmdp.utils.UserHolder;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Service;

import javax.annotation.Resource;
import java.util.Collections;
import java.util.List;
import java.util.Set;
import java.util.stream.Collectors;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
public class FollowServiceImpl extends ServiceImpl<FollowMapper, Follow> implements IFollowService {


    @Resource
    private StringRedisTemplate stringRedisTemplate;
    @Resource
    private IUserService  userService;

    /**
     * 关注或取关
     * @param followUserId
     * @param isFollow
     * @return
     */
    @Override
    public Result isFollow(Long followUserId, Boolean isFollow) {
        if(isFollow==null||followUserId== null){
            return Result.fail("操作失败");
        }
        //获取当前用户Id
        Long userId = UserHolder.getUser().getId();
        if(isFollow){
            //先查询是否关注 避免并发错误
            int count = query().eq("user_id", userId).eq("follow_user_id", followUserId).count();
            if(count>0){
                return Result.ok("已关注");
            }
            //关注
            Follow follow = new Follow();
            follow.setUserId(userId);
            follow.setFollowUserId(followUserId);
            boolean flag = save(follow);

            if(flag){
               stringRedisTemplate.opsForSet().add("follows:"+userId, followUserId.toString());
            }
        }else {
            //取关
            boolean flag=  remove(new QueryWrapper<Follow>().eq("user_id", userId).eq("follow_user_id", followUserId));
            if(flag){
                stringRedisTemplate.opsForSet().remove("follows:"+userId, followUserId.toString());
            }
        }
       return Result.ok();
    }

    /**
     * 查询是否关注
     * @param followUserId
     * @return
     */
    @Override
    public Result followOrNot(Long followUserId) {
        Integer count = query().eq("user_id", UserHolder.getUser().getId()).eq("follow_user_id", followUserId)
                .count();
        return Result.ok(count>0);
    }

    /**
     * 查询共同关注
     * @param id 被查询的用户id
     * @return
     */
    @Override
    public Result queryCommonFollow(Long id) {
        Long userId = UserHolder.getUser().getId();
        String key = "follows:"+userId;
        String key2 = "follows:"+id;
        Set<String> ids = stringRedisTemplate.opsForSet().intersect(key, key2);
        if(ids==null||ids.isEmpty()){
            return Result.ok(Collections.emptyList());
        }
        List<Long> usersIds = ids.stream().map(Long::valueOf).collect(Collectors.toList());
        //获取用户信息
        List<User> users = userService.query().in("id", usersIds).list();
        List<UserDTO> userDTOS = users.stream()
                .map(user -> BeanUtil.copyProperties(user, UserDTO.class))
                .collect(Collectors.toList());
        return Result.ok(userDTOS);
    }
}
